const Koa = require('koa');
const app = new Koa();
const router = require('koa-router')();
const debug = require('debug')('demo:server');
const http = require('http');

const json = require('koa-json');
const bodyparser = require('koa-bodyparser');
const logger = require('koa-logger');
const staticFiles = require('koa-static');
const apis = require('./api');

// middlewares
app.use(bodyparser());
app.use(json());
app.use(logger());
app.use(staticFiles(__dirname));

// logger
app.use(async (ctx, next) => {
  const start = new Date();
  await next();
  const ms = new Date() - start;
  console.log(`${ctx.method} ${ctx.url} - ${ms}ms`);
});

app.use(async (ctx, next) => {
  ctx.set({
    'Access-Control-Allow-Origin': '*',
    'Access-Control-Allow-Headers': 'Content-Type, Content-Length, Authorization, Accept, X-Requested-With , yourHeaderFeild',
    'Access-Control-Allow-Methods': 'PUT, POST, GET, DELETE, OPTIONS'
  });
  if (ctx.method === 'OPTIONS') {
    ctx.status = 200;
  } else {
    await next();
  }
});

router.use('/mock', apis.routes(), apis.allowedMethods());

app.use(router.routes(), router.allowedMethods());

// Error handling
app.on('error', function (err, ctx) {
  console.error('server error', err, ctx);
});

/**
 * Get port from environment and store in Express.
 */
var port = normalizePort(process.env.PORT || '3000');

/**
 * Create HTTP server.
 */
var server = http.createServer(app.callback());

/**
 * Listen on provided port, on all network interfaces.
 */
server.listen(port);
server.on('error', onError);
server.on('listening', onListening);

/**
 * Normalize a port into a number, string, or false.
 */
function normalizePort(val) {
  var port = parseInt(val, 10);

  if (isNaN(port)) {
    // named pipe
    return val;
  }

  if (port >= 0) {
    // port number
    return port;
  }

  return false;
}

/**
 * Event listener for HTTP server "error" event.
 */
function onError(error) {
  if (error.syscall !== 'listen') {
    throw error;
  }

  var bind = typeof port === 'string' ? 'Pipe ' + port : 'Port ' + port;

  // handle specific listen errors with friendly messages
  switch (error.code) {
    case 'EACCES':
      console.error(bind + ' requires elevated privileges');
      process.exit(1);
      break;
    case 'EADDRINUSE':
      console.error(bind + ' is already in use');
      process.exit(1);
      break;
    default:
      throw error;
  }
}

/**
 * Event listener for HTTP server "listening" event.
 */
function onListening() {
  var addr = server.address();
  var bind = typeof addr === 'string' ? 'pipe ' + addr : 'port ' + addr.port;
  debug('Listening on ' + bind);
}